In my experience of doing numerous studies on consumer perceptions of organic foods, I've found a strong "halo effect." That means the positive word "organic" acts as a halo and makes everything else about organic appear good even if it's not. The result is that people often believe a lot of things about organic that aren't true.
This piece by Christie Wilcox on the Scientific American blog ably dismantles two widely perceived myths about organic food: namely that organic foods don't use pesticides (they do) and that natural pesticides are less toxic than synthetic pesticides (they aren't).